Method of setting small objects in malleable sheet material and apparatus for carrying out the method

ABSTRACT

A method and apparatus for setting small gem stones in malleable material including precious metals such as gold sheets, so as to form lockets, pendants and other jewelry. Sheet material thinner than used in a completely hand-set operation is pressed to form a recess for the gem, and projections around the recess. The stone is deposited in the recess and the assembly is pressed in a jig, causing the projections to become deformed and form claws over the gem stone edge, setting it in the sheet.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method and apparatus for setting smallobjects in malleable material, and it also relates to malleable sheetmaterials in which small objects are set.

2. Description of the Related Art

More specifically, but not exclusively the invention relates to thesetting of gem stones in precious and semi-precious metal (such as goldand silver and their alloys) sheets, which are commonly used in thejewelry industry. Examples of items of jewelry incorporating set gemstones includes pendants, lockets, brooches and the like.

Although the following discussion relates predominantly to the settingof diamonds in gold, it will be appreciated that the invention has muchwider application, and indeed may be used to set any stone or othersuitably shaped and sized objects in any malleable sheet material.However, the invention has most suitable application in the jewelryindustry as described hereinafter.

The setting of gem stones in precious metals such as gold and silversheet is currently a highly skilled process. To set a stone, a holesmaller than the stone is drilled through the metal sheet in which thestone is to be set, and the upper edges of said hole are then chamferedinwardly of the hole such that the stone will seat correctly in anupright position. It should be pointed out that in most cases, thestones to be set are minute, and the sheet is as thin as possible (tokeep the cost of the sheet down as much as possible) and thus theintricacy of the process is often extreme.

A metal scoop is used to gouge metal from the sheet around the hole in adesired pattern, for example a four-pointed star, to enhance theaesthetic effect of the setting.

In order to ensure that the stone is set in its upright orientation, thesetter may use a tacky material such as Plaszicine® or Blu-Tack® to lifta stone by its upper face and place it into the chamfered hole, which isusually at the centre of the gouged pattern. The tacky material adheresmore to the finger of the setter than to the stone, and thus the slidingof the finger away from the stone once positioned in the chamfered holereleases it from said tacky material.

To secure the stone to the metal, a further gouging process is requiredwherein the setter uses a metal scoop to gouge material from around thehole towards the stone in a manner similar to the scooping of buttercurls. In the case where a four-pointed star pattern has been previouslygouged around the hole, the setter positions the stone in said hole andgouges metal from between the points of the star in a symmetricalmanner. The natural deformation of the metal which results from saidscooping is to curl in the direction of and over an edge of the stone,thus securing said edge. The setting process is completed by using ade-burring tool which is simultaneously rotated and urged downwardlyonto each of the gouged metal portions which overlie the edges of thestone. Burr resulting from the gouging operation is removed, and thedownward pressure on the malleable material deforms the gouged metalportions into small pips which overlie the edges of the stone thussecuring it symmetrically in the hole.

The abovementioned process has a number of inherent disadvantages.Firstly, there is a limit to the thickness of the metal which may beused, as thinner metal is likely to be punctured and ruptured by themanual gouging operations, regardless of the skill of the setter, butreducing the thickness of the material is always desirable especially incases where a large number of lockets, pendants, brooches and the likeare produced (of the order of thousands per week), in that a slightreduction in the thickness of the metal of said items may represent asubstantial saving in raw material cost for the manufacturer.

A further disadvantage which is inherent in any manual operation is theimprecise nature thereof. More specifically, it is highly unlikely thata setter will achieve an exactly symmetrical stone setting on everysingle occasion, and in some cases such variation may result in weaksetting of the stone with obvious further consequences.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a method of setting a stonein the sheet whereby the skill level required in the setting of stonesis reduced, and to improve the consistency and quality of the setting ofthe stone.

It is a further object of the invention to provide a method for settingstones in malleable material which allows stones to be set in materialsof a lesser thickness than previously possible by manual gem settingoperations.

The invention also provides an article comprising a small object set ina sheet of malleable material.

According to a first aspect of the invention there is provided a methodof manufacturing an article such as item of jewelry, wherein a smallobject, such as a precious, semi-precious or quasi-precious stone, isset in a sheet of malleable material, such as a precious metal or analloy thereof, characterised in that prior to the insertion of theobject, the sheet is machine or jig worked to be provided with a recessor aperture sized to the size of the small object, and peripherally ofthe aperture or recess, with two or more projections which project fromone face of the sheet, and wherein the small object is deposited in therecess or aperture and a tool presses on the projections which deformsthe projections over the edge of the small object to set same in thematerial.

Preferably, the sheet with the object located therein is held in a jigwhich is located in a predetermined position in relation to the tool,which is mounted for movement towards the jig to effect the deformingstep, and is movable away from the jig after the deforming step toenable the sheet to be removed from the jig.

It is further preferable that the tool comprises first and secondportions which are relatively moveable against spring loading, whereinthe first portion comprises a pin which engages the small object whenthe tool is moved to perform the deformation step, and the secondportion performs the deformation, after the first portion engages andlocates the small object, by sliding relative to the first portion,against the spring loading.

Preferably, the jig defines a support means which engages the rear faceof the sheet behind the projections which causes the deforming materialto move in a direction to lie over the edge of the small object.

Yet further preferably, there are recesses in the rear face of the sheetbehind the projections thereof, and the jig is provided with protrusionswhich form said support means and protrude into said recesses.

Preferably, the sheet is pressed to define a recess for the object, andthe projections.

According to a second aspect of the present invention, there is providedapparatus for manufacturing an article such as an item of jewelrywherein a small object, such as a precious stone, is set in a recess oraperture provided with two or more projections adjacent thereto and in afront face of a sheet of malleable material, such as a precious metal oran alloy thereof, comprising a deforming tool and a jig which may bemoved together and apart, the jig being located in a predeterminedposition in relation to the tool, there being recesses in the rear faceof the sheet behind the projections thereof, the jig being provided withprotrusions which form said support means and protrude into saidrecesses, the tool pressing on the projections of the material to deformsaid projections over the edge of the object when positioned in saidrecess and said material is positioned on said jig, characterised inthat the jig defines a support means which engages the rear face of thesheet behind the projection or projections which causes the deformingmaterial to move in a direction to lie over the edge of the smallobject.

Preferably the tool comprises first and second portions which arerelatively movable against spring loading, the first portion comprisinga pin adapted to engage the object deposited in the recess or apertureof the material when the tool is moved to perform the deformation step,and the second portion performing the deformation of the projection orprojections over the edge of said object after the first portion engagesand locates the small object, by sliding relative to the first portion,against the spring loading.

The invention has advantage in that as the sheet is pre-worked bymachine and/jig, stones may now be set in metal of a thickness as low as0.216 mm ({fraction (6/1000)} of an inch), and possibly lower.Typically, skilled workers are currently capable of setting stones inmetal of minimum thickness of the order of 0.590 mm ({fraction(15/1000)} of an inch). It is to be understood that these values ofthickness are provided only as a guideline and to demonstrate that thesetting of stones according to the invention may now be effected inmetal of a substantially lower thickness than by manual methods.

Furthermore, the invention provides a means of setting stones inmalleable material quickly and effectively without the requirement forespecially skilled labour, and the setting of the stone is generallymore secure than that achievable by a skilled craftsman.

The invention also provides an article comprising a sheet of malleablematerial in which a small object is set, the object being held to thesheet by two or more portions of the sheet pressed out of the sheet anddeformed over the edge of the small object.

Preferably, the article is an article of jewelry, the sheet is ofprecious metal or an alloy thereof, and the small object is a gemstone.

Preferably, the sheet is of a thickness of the order of 0.236 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

A specific embodiment of the invention will now be described by way ofexample with reference to the accompanying drawings wherein:

FIG. 1 shows a perspective view of a tool according to the invention;

FIG. 2 shows an enlarged plan view of the recess in the malleablematerial and a gem stone positioned therein;

FIG. 3 shows a sectional view of the recess and stone of FIG. 2 prior tothe deformation of the projections, and

FIG. 4 shows a sectional view of the recess and stone of FIG. 2 afterthe deformation of the projections.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring firstly-to FIG. 1, a gem setting -tool denoted generally at 2comprises a base plate 4 containing a jig 6 mounted at an angle θ to theplane of the base plate 4. A heart-shaped plinth 8 is mounted on saidjig 6 and a similarly shaped pendant 10 with upper face 12 and a lip 14made of gold or other malleable sheet material is mounted thereon. Thependant 10 is provided with the lip 14 around the extent of itsperiphery and said lip 14 aids in the positioning of said pendant onsaid plinth.

The upper face 12 of the sheet material of the pendant 10 is providedwith a star-shaped recess 16 for receiving a suitably sized gem-stone 19and also with projections, one of which is referenced at 18, whichsurround said recess. It is to be noted that the sheet of the pendant ispre-formed with the recess prior to inserting the gem 19 (FIGS. 2 and3). This pre-forming in accordance with the invention is by machineand/or jig working so that the recess will be formed accurately, andmore particularly will enable the use of much thinner gauge sheetmaterial, which, if of precious metal or an alloy thereof will be veryexpensive. It is preferred that the recess and projections be formedsimultaneously by pressing the sheet material.

The tool 2 also comprises a vertically moveable plate 20 slidablyconnected to a handle 22 with a grip 24 which is intended to be operatedby a human hand (not shown). Rotation of the handle 22 in the directionshown by arrow 26 about a hinge 28 urges the plate 20 towards the jig 6,and rotation in the alternate direction moves the plate away from saidjig. True vertical motion of said plate is ensured by spigots 30provided on the end faces of the plate 20 and which slide in slots 32 ina pair of end blocks 34 attached both to the base plate 4 and to a backplate 36 of the tool 2.

The vertically moveable plate 20 is provided on its underside with a peg38 within which a pin 40 is loaded with a spring 42 and is allowed totranslate. The base of the peg 38 is chamfered inwardly as shown in FIG.3 at 39.

Referring to FIG. 2, the star-shaped recess 16 in upper face 12 is shownwith gem stone 19 located therein.

With reference to FIGS. 1 and 3, the operation of the tool is nowdescribed. A pendant 10 is positioned on the plinth 8 as shown. Theplinth is located on the jig 6 to ensure that the pin 40 is directlyabove the centre of the recess 16 and during operation the pin willcontact the upper face of any gem stone located therein. Once such astone has been deposited in the recess 16 in the correct orientationshown in FIGS. 2 and 3, the handle 22 is rotated and the peg 38 is movedvertically towards the pendant. At a certain point in the verticaltravel of the plate 20, and thus the peg 38, the pin 40 comes intocontact with the upper face of the gem stone 19 and thus holds itagainst the bottom of the recess. When the plate 20 is almost at thelimit of its downwards vertical travel, the position shown in FIG. 3 isreached. It can be seen from this Figure that the plinth 8 is providedwith protrusions 9 which are received by the hollows in the underside ofthe pendant 10 resulting from the pressing of projections 18. Saidprotrusions further aid the positioning of the pendant 10 on the plinth8, but more importantly prevent the metal of the strip from being pushedback into the hollows during the deformation of the projections 18 aswill be explained.

In the final forming step the pin is forced to its lowermost position asshown in FIG. 4. The diameter of the peg 38 is marginally greater thanthe diagonal distance between opposing projections 18 such that thechamfered portions 39 of the peg 38 press on the projections and urgethem inwardly over the edges of the gem stone 19, trapping it to thesheet. The malleability of the material of the pendant is such thatlarge forces are not required.

The position of the peg and pin immediately after the deformation of theprojections 18 is shown in FIG. 4, where it can be seen that the gemstone 19 is secured within the recess 16 by the deformed projections 18which overlie the edges of said stone.

It will be appreciated that although a hand operated tool has beendescribed herein, any suitable actuation means, for example hydraulic orpneumatic, may be used to move the plate 20 in a vertical direction.

What is claimed is:
 1. A method of manufacturing an article comprising asheet of malleable material in which a small object comprising aprecious stone is set, wherein prior to the insertion of the object, thesheet is initially worked to form a recess sized to the size of thesmall object and one or more projections formed peripherally of therecess and which project from one face of the sheet above the recess,and wherein the small object is deposited in the recess, said sheetbeing mounted on a jig located in a predetermined relation to a toolmounted for movement towards and away from the jig, said tool comprisinga pin relatively moveable within and which protrudes from one end of apeg, a lower surface of the said one end of said peg being inwardlychamfered, the mounting of the tool and the jig ensuring that as thetool moves towards the jig, the pin firstly comes into contact with thestone and clamps the stone in the recess, and secondly the inwardlychamfered lower surface of the peg contacts the one or more projectionsof the sheet material and deforms the one or more projections over edgesof the stone, and wherein the jig is provided with a recesscorresponding to and receiving the recess in the sheet material andhaving at least one or more protrusions, which are received in cavitiesunderneath the one or more projections in the sheet material and whichconstrain the material during the deforming of the projections of thesheet material over the edges of the stone.
 2. The method according toclaim 1, wherein said sheet of malleable material which is worked toform a recess comprises a precious metal.
 3. The method according toclaim 2, wherein said precious metal comprises one of gold and a goldalloy.
 4. An apparatus for setting a small stone in a sheet of malleablematerial provided with a recess having one or more projections adjacentthereto and in a front face of the sheet of malleable material whichnecessarily has one or more recesses in a rear face of the sheetcorresponding to the projections in the front face thereof, wherein thesmall stone is deposited in said recess prior to setting, said apparatuscomprising: a deforming tool and jig which are movable together andapart, the jig being located in a predetermined position in relation tothe tool, the jig being provided with a predetermined number ofprotrusions which form supports for and protrude into said one or morerecesses, the tool being mounted in said apparatus so as to be moveabletowards and away from said jig, and the tool comprising a peg in which apin is mounted and which protrudes from one end of said peg and ismoveable axially relative to said peg, the said one end of said peghaving an inwardly chamfered surface, said tool being lowered until saidinwardly chamfered surface comes into contact with said one or moreprojections in the front face of the sheet of malleable material, andwherein the predetermined number of protrusions in the jig constrain thematerial of the sheet in the region of the said one or more projectionsduring the deforming of said at least one or more projections of sheetmaterial over edges of the stone.
 5. An apparatus according to claim 4,wherein the mounting of the pin within the peg of the tool is springloaded to bias the pin outwardly of said peg, the movement of the pinbeing relative to the Reg when the pin comes into contact with the smallstone occurring against the action of the spring.
 6. The apparatusaccording to claim 4, wherein said malleable sheet material having arecess therein comprises a precious metal.
 7. The apparatus according toclaim 6, wherein said precious metal comprises one of gold and a goldalloy.